The U.S. leads the world in monkeypox cases: How did this happen?


Tracking monkeypox’s spread: The data behind how the U.S. came to lead the world in cases

The United States has failed to curb its monkeypox outbreak and currently leads the world in total cases.

As of Aug. 18, 13,514 monkeypox cases have been confirmed in the U.S., according to Grid’s tracker of the Centers for Disease Control and Prevention data — nearly twice as many cases as any other country. This is despite having advanced warning, preexisting vaccines and the fresh experience of dealing with the covid pandemic. Of course, the United States is a huge and populous country, and several European countries, including Spain, Portugal and the United Kingdom, currently have higher cases per capita. But while new cases in those countries are starting to plateau, the U.S. outbreak shows little sign of slowing down.

“I think that with the acceleration of monkeypox in the United States, as well as the deceleration in European countries, I would not be surprised if the United States took the lead [in cases per capita],” said Katelyn Jetelina, a public health researcher and author of the newsletter Your Local Epidemiologist.

Whether that ultimately happens depends on the public health response, which will hinge largely on whether those at highest risk — currently men who have sex with men — have timely access to testing and vaccines. So far, that’s been a challenge, in part because officials are still only seeing a fraction of actual cases. “We have such a fragmented and neglected data infrastructure,” Jetelina said. “We are essentially flying blind.”


Monkeypox testing is improving in the U.S., but still not great

Testing capacity has improved in the U.S. immensely since the early days of the outbreak — 80,000 PCR tests can be processed each week instead of 8,000 — but that increased capacity isn’t being fully realized.

About 40 percent of monkeypox tests are coming back positive, according to the latest CDC numbers released in early August, said Boghuma Kabisen Titanji, an infectious disease physician at Emory University. “That is very high,” she said, and suggests the true caseload in the U.S. is much higher. Clinicians and providers are “suspecting monkeypox in too few people,” Titanji said.

Known cases in the U.S. are still largely clustered around major urban centers. That pattern likely reflects a higher actual caseload in these areas, but also a greater awareness of the outbreak and easier access to testing.

“Large cities with sexual health clinics were probably able to get patients tested sooner, in part because of the doggedness of those clinicians,” said Jennifer Nuzzo, an public health researcher at Brown University. But outside these cities, providers may not be thinking to test for monkeypox or know how to access testing. That incomplete picture leaves public health officials less able to respond effectively, she said.

As imperfect as the monkeypox picture is in the U.S. and Europe, it’s much clearer than in much of West and Central Africa. While many of those countries have seen monkeypox outbreaks for decades, “testing infrastructure, for the most part, is nonexistent,” said Titanji.


What do we know about who is most at risk for monkeypox?

Detailed demographic data on who is getting monkeypox is also lacking, since many states aren’t regularly reporting that data to the CDC. But “there are major inequities emerging in terms of who is being most affected by the outbreak and who is able to access vaccines,” Titanji said.

In North Carolina, for instance, 70 percent of monkeypox cases are in Black men, but only 24 percent of vaccines have gone into Black arms, while white men have received 67 percent of vaccine doses, despite having only 19 percent of cases.

“Populations who may be more wealthy and have better access to the internet or who just have access to healthcare are the ones who get protected, instead of individuals with the highest risk,” said Titanji. “How we tackle that will definitely be a crucial point moving forward.”

What about the rest of the world?

Globally, the picture of monkeypox’s spread is similarly patchy.

Testing in many European countries has been on par with the U.S., and vaccine doses, while scarce, are available. But it’s an entirely different picture in many African countries where the monkeypox virus has been circulating for decades.

Different countries vary in their testing capacity, Titanji said, but for the most part testing is centralized in big cities, and infrastructure to confirm cases in more rural areas is often lacking. As a result, the monkeypox burden in many African countries is likely higher than reflected in official counts. And despite African countries recording the vast majority of monkeypox deaths (over 100), the continent has yet to receive a single dose of vaccine.

“To fully characterize what’s happening in historically affected countries, we still need a lot of investment in surveillance and testing,” Titanji said, “because right now we’re navigating in the dark and making assumptions on data that is not of the best quality.”

Thanks to Alicia Benjamin for copy editing this article.

  • Jonathan Lambert
    Jonathan Lambert

    Public Health Reporter

    Jonathan Lambert is a public health reporter for Grid focused on how science, policy and the environment shape our collective well-being.

  • Matt Stiles
    Matt Stiles

    Senior Data Visualization Reporter

    Matt Stiles is the senior data visualization reporter for Grid.